//
// Created by Thinkpad on 2025/10/30.


#include <iostream>
using namespace std;

void say_age(int age);

int main(int argc,char **argv) {
    int age {23};
    cout << "age - before : " << age << endl;
    say_age(age);
    cout << "age - after  : " << age << endl;
    return 0;
}

void say_age(int age) {
    ++age;
    cout << "hello! you are " << age << " years old" << endl;
}